Turbocharger systems are frequently used to improve the efficiency of internal combustion engines. Monitoring or diagnosing the performance of a turbocharger often involves measuring the rotational speed of the turbocharger. However, speed sensors can be relatively expensive and size, packaging, assembly, or installation constraints can be prohibitive. For example, some speed sensors require drilling a hole on a contoured surface of a compressor housing. While acceleration sensors have been proposed for measuring rotational speed based on a proportional relationship, the accuracy and reliability of the measurement suffers as rotational speed increases. Accordingly, it is desirable to provide a means for determining rotational speed of a turbocharger in a manner that is accurate and reliable over the turbocharger speed range while minimizing cost and packaging and/or installation constraints.